DC-magnetoencephalography (DC-MEG) technique has been refined and allows to record cortical activity in the infraslow frequency range less than 0.1 Hz noninvasively. Important questions however, remained, especially, how specific these infraslow activations can be recorded and whether different activations, for example, motor versus acoustic, can be separated. To clarify these questions, in the present DC-MEG study, cortical infraslow activity was investigated intraindividually in response to different activation modalities, that is, motor versus acoustic: in 13 individuals, 30-s periods of finger movement or listening to concert music, were interleaved for 60 min. DC-MEG was capable to resolve intermodal differences concerning the relative amplitudes, field patterns, and source localizations. These results clarify that DC-MEG allows to identify and to discriminate modality-specific infraslow cortical neuronal signals.
aDepartment of Neurology, Charite-Universitaetsmedizin Berlin
cDepartment of Neurology, Vivantes Auguste-Viktoria-Klinikum, Berlin, Germany
Correspondence to Stefanie Leistner, MD, Department of Neurology, Charite-Universitaetsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, Berlin D-12200, Germany
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Received 31 October 2009 accepted 17 November 2009